Basic winemaking comprises combining winemaking ingredients in a fermentation vessel. The mixture is left to ferment undisturbed for a period of time during which unwanted sediment know as “lees” settles. Prior to consumption, the wine must be separated from its lees. Typically, the wine is separated from the lees by siphoning the liquid, using a hose, from one container to another, leaving the lees behind. The siphoned liquid may then be passed through a filter to ensure that any lees that is stirred up in the siphoning process does not contaminate the wine that is ready for the next step in the particular winemaking process.
A substance such as Bentonite, activated carbon or other suitable clarifying agents may be introduced to the liquid to encourage further sediment to form during a process known as fining. The liquid may then undergo a second fermentation period. After this secondary fermentation period, the liquid is ready for bottling, or for another fermentation period.
U.S. Pat. No. 3,760,711, issued in the name of Webster, discloses an apparatus comprising two plastic bag containers having a fitting adapted to accommodate a tube to siphon the liquid from one container to the other using gravitational feed.
There are also several known fermentation tanks that are modified to separate the wine from its lees without the need of a siphoning tube. U.S. Pat. No. 4,164,902 issued in the name of Maarleveld, discloses a wine fermentation container that filters the lees from the wine as the wine flows out of the container into a second container. The container has an inverted frusto-conical shaped bottom section and a bottom discharge opening. A filter is positioned within the tank just above the bottom discharge opening. The filter is sealingly engaged at its lower edge with the frusto-conical shaped bottom section to retain the lees as the wine flows out of the container into a second container.
Canadian Patent No. 2,227,023, issued in the name of Barrios, discloses a fermentation container that allows the removal of the lees and leaves the wine behind in the fermentation container. The container has an inverted frusto-conically shaped bottom that leads to a valve that has an outlet that is sufficiently large to allow the lees to pass through. After the concentrated juice is left to ferment and the lees is allowed to settle at the bottom of the container, the valve is opened and the lees carried by a portion of the wine that flows out the bottom of the container and into a waste container. Once the last of the lees flows from the container, the valve is closed and the remaining wine is left in the container.